1. Field of the Invention
This invention relates generally to the computer control printing, displaying, or other presentation of documents which may have text, graphical components, and/or images. This invention is more particularly related to a system and method for defining and using resources in a document processing language.
2. Discussion of the Background
A Standardized Page Description Language ("SPDL") has been proposed and is being developed as an international standard by the International Standards Organization ("ISO"). The draft is known as ISO/IEC DIS 10180, labeled "Information Processing Text-Communication Standard Page Description Language" and is available through the American National Standards Institute ("ANSI") in New York. The current version of this draft is dated March, 1991.
Chapter 7 of the current version of ISO/IEC DIS 10180 pertains to resources in the SPDL. A resource is defined as an information object which may be available in the environment of the presentation process. The resources defined by the proposed international standard include resources related to fonts, glyphs, color spaces, data sources, filters, patterns and forms. The presentation process refers to the processing of a document so that it can be presented. The word "presented" includes any manner of displaying or printing or transmitting a document for display or printing and includes displaying on a CRT, printer, fax machine, or any type of presentation device.
While ISO/IEC DIS 10180 describes the resources and how they are used, it does not describe how the processing of resources is to be implemented.
PostScript.RTM. is a page description language developed by Adobe Systems Inc. Section 3.9 of "PostScript Language Reference Manual" second edition, 1990, describes how resources are used in PostScript, Level 2. However, SPDL has a hierarchical structure whereas PostScript does not. Accordingly, the processing of resources in PostScript may not be appropriate for use in a hierarchical language such as SPDL.
Interpress.RTM. is a page description language developed by Xerox. However, Interpress does not have different processes for distinguishing resources, putting the resources into the processing environment, and the process to make the resources in the environment available to the content of the document.